From another Deadline article on Parrot:
The firm's Global Television Demand Report measures demand for all digital original series across 10 global markets, monitoring the various ways consumers express their interest in a piece of content across streaming platforms, on social media, on blogs and elsewhere. The popularity of these shows plays a key role in the success of these on-demand platforms.
So they're measuring interest based entirely on activity on the platform and OUTSIDE the platform. It's a bizarre way to gauge the interest in something because it may not actually be representative of viewership. Monitoring 'viewers' on these platforms is incredibly ambiguous b/c none of them disclose how they determine an actual viewer. Supposedly Netflix bases it on who actually finishes a show, but if 5% at least watch 3 episodes of a 10 episode show does that discount their viewership?